Composition material adapted to the plastic art



. 3i? process and product disclosed in sai Patented May 29, 1928,

UNITED STATES 1,e11 ,2z9 PATENT OFFICE.

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COMPOSITION MATERIAL LDAP'IED TO THE PIiABflIC ART.

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This invention relates to improvements in composition material adapted to the plastic art and in methods of producing such material.

I In my copending application, Serial No.

646,235 filed on .even date herewith, are disclosed and claimed certain improvements over the processes and products set forth in.

such improvements being disclosed but not claimed in my copending application aforementioned.

50 Another and more specific object-is that of providing improved plastic materlals capable of induration under the influence of heat.

Another object is that of providing advantageous and simplified processes of producing such materials. I

Other objects and advantages of the-present invention will hereinafter appear.

While the materials and processes disclosed in said'patent and also the vim roved Nash application have proven of greatvalue and have been extensively used industrially, the processes disclosed have been unduly complicated, expensive and time consuming,

whereas by the new process herein contemplated it has been found possible not only to simplify the method of production of the material as well as reduce the time. labor and expense involved in production thereof 40 but also to produce a superior product.

According to the teaching of the Steinberg patent, a relatively inert filler material. such for example as asbestos. is impregnated with a composition binder comprising among other ingredients approximately equal portions of stearine pitch and coal tar pitch, these. substances constituting the major constituents of the binder. In the application of Nash. a portion of the coal tar pitch is replaced bv an asphaltic body such for example as gilsonite whereas cer tain further variations and improvements not herein important are contemplated.

However, both said patent and said application contemplate the use in the binder Application fled June 18, 1923. Serial .ll'o. 640,884.

of very substantial proportions of coal tar pltch and this substance, under the treatment nnposed, precipitates large quantities ofcarbon which if permitted to remain in situ has been found uite deleterious to the product 1n matters 0 strength and the like. Therefore both the patent and application aforesaid teach as an important step in their respective processes that of removing such free carbon which as stated is likely to be 5 precipitated to the extent of 30% b weight of the coal tar pitch employed, w ereas in practice it is now known that this amount of free carbon may and frequently does app'rpiimate 50% by weight of the coal tar 7 P c v This procedure obviously involves loss of a relatively high percentage of the material since the carbon so removed is of little or no-commercial value. Also the ste s necessary for such removal are quite di cult, expensive and time consuming, since the carbon has a tendency to settle and adhere to the lower portions of the tank, still or the like in which the binder is formed, necessitating considerable labor for its removal, whereas the container is frequently very much damaged by the rough treatment incident to such removal.

According to the herein contemplated method, I am able to obviate entirely the aforementioned procedure for removal of free carbon. whereas, as a result of the aforesaid method I am also able to obtain a product adapted to all or practically all uses to which the earlier products are applicable and moreover possessing advantages there over.

Thus in accordance with the herein contemplated procedure, suitable proportions of stearine pitch, a solidifiable substance such for example as castor oil, China-wood oil or the like, and an agent such as sulphur adapted to promote induration under the influence of heat are brought together under suitable conditions of temperature or the like for production of a molding compound or a binder therefor in the absence of coal tar'pitch or in the absence of a suf ficient quantity of the latter to involve precip tation of a material quantity of carbon under the treatment imposed. Additionally, a quantity of a suitable plasticizing agent such for example as iron oxide may be preferably included to promote flow of the ma- 110 terial and treatment preferably after removal of formed piece from the forming mstrumenenerally to facilitate molding thereof. Also in certain cases it m3 be found desirable or advantageous to d a suitable quantity of a solvent substance such for example as benzol.

In those cases wherein a relatively inert filler such for example as comminuted asbestos is incorporated with the aforedescribed plastic material prior to mold ng thereof the sulphur or other solidifying agent and also the plasticizing a cut and solvent substance may be preferab y mixed with such filler prior to incorporation.

The aforedescribed plastic material preferably after incorporation with a sultable filler, is adapted to form-givingtreatment under pressure with strong heat indurattpn tality.

During such heat indurat on treatment the sulphur or other solidifylng agent appears to act upon or with reference to certain of the other constituents of the maternal particularly the solidifying oil or the like, whereby the material of the piece is transformed into a hard and durable cenditon exhibiting superior strength with resistivity toward the action of chemical agents and solvents.

As t pical of certain preferred methods of pro ucing the herein contemplated product the following steps may be employed. Approximately 100 parts of stearine pitch and parts of castor oil may be thoroughly mixed at a temperature of about 475 degrees F., the mixture being thereafter permitted to cool to about 200 degrees F. and thereafter substantially parts of benzol are added with stirring.

For production of such a molding comund a proximately 286 parts of the stearme itc oil. and benzol mixture, taken as a inder is thoroughly mixed and incorporated with approximately 1100 parts of asbestos. or equivalent filler material, 66 parts of sulphur and 22 parts of iron oxide being added. Such mixing and incorporation of the foregoing ingredients may be facilitated by further additions of benzol up to or even somewhat in excess of 100 parts. The mixture may be then disintegrated, screened and subjected to other desired known treatment preparatory to molding. Also it is preferable that an appreciable interval of time such for example as 12 hours intervene between compounding of the molding material and actual pressing thereof.

The material may be pressed in 'cool or cold dies underconditions similar to those ordinarily employed in treatment of analogous molding mixes.

Following molding the material is subjected to strong heat induration treatment which may cover a period of hours up to or even beyond 24 hours at temperatures which are preferably elevated gradually from approximately 200 degrees F. to a final temperature of about 500 degrees F.

Pieces produced in the manner aforedescribed are characterized by superior strength and resistance to impact. Also such pieces have been found to undergo in general more uniform shrinkage during cure than do pieces composed of materials prepared in the ordinary known ways,

whereas the pressing qualities of the material are found tobe superior.

While the aforementioned proportions of the various ingredients have been found to be desirable and advantageous, it is nevertheless to be understood that such proportions may vary rather widely, whereas for certain special purposes radically different proportions may be found desirable.

Thus an advantageous compound characterized by high plasticity, superior molding properties and relatively low shrinkage during induration may be produced by treating inthe manner aforedescribed approximately 600 parts of stearine pitch and 120 parts of castor oil together with 137 parts of a solvent such as benzol, and incorporating with substantially 286 parts of the binder so produced 1100 parts of asbestos or a similar filler material together with 90 parts of sulphur, 20 parts coal tar oil and either with or without an additional quantity of benzol or an equivalent solvent up to 150 parts.

As a further variant of the foregoing: 100 parts of stearine pitch and approximately 20 parts of castor oil may be brought together as in the preceding examples to produce a compound which, when incorporated with a suitable filler, is well adapted to form giving treatment and heat induration, preferably enacted subsequently to forming.

It is of course to be understood that the terms stearine pitch and others mentioned herein are intended to designate the substances obtamable commercially.

What I claim as new and desire to secureby Letters Patent is 1. Composition material adapted to heat induration, consisting of approximately, 100 parts of stearine pitch, 10 parts of castor 011, 25 to 100 parts of benzol, 66 parts of sulphur, and 22 parts of iron oxide.

2. A hard substance which is the heat induration residuum of heat induratable material including a binder composed of approximately 100 parts of stearine pitch, 10 parts of castor oil and 25 to 100 parts of benzol, 286 parts of said binder being mixed with about '66 parts of sulphur, 22 parts of iron oxide, and 1100 parts of asbestos.

3. The process of producing cold molding plastic composition material, which consists in bringing together under conditions of temperature control about 100 arts of stearine pitch, 10 parts of a soli ifiable oil, at least 25 parts of ,a solvent and about 66 parts of a substance adapted under influence of heat to act as a hardening agent, and indurating the product by strong heat treatment. 7

4. The process of producing cold molding plastic composition material, which consists 1 in bringing together under conditions of temperature control to form a. binder about 100 parts of stearine pitch, 10 parts of castor oil, and at least 25 parts of benzol, mixing with 286 parts of said binder about 66 parts of sulphur, 22 parts of iron oxide, and about 1100 parts of asbestos, molding the material while cold, and then indurating the molded material by strong heat treatment.

In witness whereof, I have hereunto subscribed my name.

CLETUS r. CHOSA. 

